Aerial missile



July 7, 1953 L. s. BILLMAN' 2,644,

AERIAL MISSILE F'il ed Oct. 1, 1948 I 2 Sheets-Sheet 1 Bowen 20:

m HZ imam July 7, 1953 s. BILLMAN 2,644,396

AERIAL MISSILE Filed Oct. 1, 1948 v 2 Sheets-Shet-Z Loud 82352 ma a A Patented July 7, 1953 I II I AERIAL MISSILE I I Louis S. Billman, Glastonbury, Conn, assignor to United Aircraft Corporation, .East Hartford, Conn, a corporation of Delaware This invention relates to a combination pulse jet and ram. jet. I

Itis well known that a ram jet is normally capable of sustained self-propelled motion only above a predetermined speed, and. the vehicle incorporating the ram jet must 'be accelerated to a speed above that minimum before the ram jet willbe effective. A feature of this invention is an arrangement for driving the ram jet by an-' other type of power plant until it exceeds the predetermined minimum speed after which the ram jet is disconnected from the other power plant.

It is possible to ferry a ram jet by airplane until .the desired minimum speed for the ram yet is reached, but with such arrangement, the ferrying vehicle is not normally disposable by reason of initial cost and the presence of a pilot. A feature of the invention is the use of a low-cost, short-life power plant as the ferrying vehicle so that it may be expendable when the ram jet has reached operative speed.

One feature of the invention is an arrangement I for automatically disposing of the accelerating or starting power plant by causing it to be ejected fromthe ram jet when the latter becomes operative.

from the specification and claims and from the accompanying drawings which illustrate an embodiment of the invention.

Fig. 1 is a side view of the device.

Fig. 2 is a sectional view through the ram jet the discharge end. The pulse jet carries larger stabilizing fins 14 which, as will be apparent later,

are disposable with the pulse jet when the ram jet has been accelerated to an operative speed.-

As shown in Fig. 2, the ram jet part of the missile includes a central substantially cylindri-g cal member it which functions as a container for fuel and for the controls and which may carry a war-head I8, as will be apparent. The

member I6 has a conical leading end 20 and a conical downstream end 22. The container is Other objects and advantages will be apparent;

7 Application October 1,1948, Seria1 No.5 2,170'

r 9 Claims. (01.102-49) surrounded by an outer shell 24 spaced from the container and defining an annular path 26 for the ram jet. Air enters the leading end of the annular space 26 and flows therethrough past fuel nozzles 28 located forwardly of the downstream. cone 22. Struts 30 may support the shell in predetermined spaced relation to the inner member.

The thrust nozzle 4 forms a rearwardly projecting extension of the, outer wall 24 which, as shown, may be double-walled with aispace 32 therebetween. The inner wall 34 of the outer shell may be reduced in diameter adjacent to the cone 22 for a more effective path of flow for the gas through the ram jet. In the thrust nozzle 4, the inner wall of the outer shell 32 has an inner lining 35 (Fig. 3) closely spaced from the inner wall34 to form a flow path for boundary layer air which enters at the forward end of the liner 36 and cools the liner and the inner wall. The lining 36 is spaced from the inner'wall at its rearward end for the escape of boundary layer air. In orderto provide proper spacing for the lining 36 conventional streamlined struts or spacers (omitted for convenience) may be utilized as for example struts similar to the spacing struts over-the end of cone 22 and limits the forward movement of the pulse jet within the thrust nozzle '4. A typical example of such valves is clearly shown in Patent No. 1,586,226 issued May 25, 1926. The valve 38 may comprise a group of flapper-type valves or reed type valves which may" have a. slight bias toward the closed position.

Such valves are conventional and well known in:

the art. The valves 38 are supported at-the for--- ward end of a sleeve 42 which forms the combus tion chamber 44 for the pulse jet and which is connected at its rearward end with the duct 46 forming the thrust nozzle of the pulse jet. The duct 46 carries rollers 48 engaging with the liner 36 and supporting the pulse jet for axial movement within the thrust nozzle 4. the streamlining of the device, a frusto-conical sleeve 49 is mounted around the downstream end of the thrust nozzle 46 and engages at its forward end with the discharge end of the thrust nozzle.

4. The sleeve 49 carries the fins [4, above mentioned, and provides for augmentation of the flow through the duct, the air entering said sleeve I through the" cooling air space around the liner 36', and'also, if desired, through forwardly ar For improving 3 ranged openings outwardly of the thrust nozzle 4 at the inlet end of the sleeve 49.

In operation, in starting the device, the pulse jet is set in operation by the ignition of fuel injected intermittently through nozzles 5|, preferably located in the supporting structure for the ring of valves 38. The fuel may be supplied through passage 52 in the cylindrical member l6 and the valve structure. is provided in the combustion chamber 44 to ignite the fuel and thus provide for an inter?" mittent discharge of gas through the thrustnozzle 46. Air enters the pulse jet by passing through the ram jet and providesfor Qhflratiom of the pulse jet for the purpose of'startingthe. missile in flight and for accelerating the ram jet.

to an operative speed for the ram jet. When the, ram jet reaches operative speed, fuel is injected through the nozzles 28 by means of an airspeed responsive device which may have a predetermined ai rspeed or Mach number setting.- of the well known spring loaded mechanisms or a diaphragm subjected to Pitot tube. pressures may be utilized. The fuel is ignited either by the ignitor53 or by the combustion in the chamber 44.. In either event, the air passing through the ramjetultimately exerts a rearward thrust-on the pulse jet greater than the forward thrust exerted by the p'ulsejet and forces thepulse jet axially rearwardly withinthe thrust nozzle 4 thereby ejecting it and allowing the ram jet to becomes effective. Obviously, a suitable mechanism, not shown, provides for closing the fuel passage-'52 when the pulse jet is ejected as for example by; tripping a spring loaded valve in re sponse-to the, actuating movements of above mentioned airspeed responsive device which actuatesthe fuel injectionmeans for the ram jet. It willbe apparent that the pulse jet is, retained the ram jetA onlyby the thrust'exerted by the pulse jet, and, as the ramjet ram air pressure increases, the pulse jet is readily ejected. It should be noted that the static rampressure in theram jetwill increase Withcontinued increase in fiig ht speed of the combined missile so that eventually sufilcient ram pressure is developed to eject the pulse jet. The entireoperationis most clearly understood under the condition where the fuel is simultaneously injected into the ram jet and; cutoff in the pulse jet. It is apparent then that the thrust of the pulse jet will immediately drop toward zero: so that the ram air pressure in thram jet will suddenly eject. the pulsev jet unit.

instead ofv a series. of valves disposable with the pulse jet, the set. of; valves may be replaced by abankof valves which remain inthe ram jet, as;

shown in Figs. 4 and 5, in which thevalve ele ments idarein the form of streamlined vanes pivoted on substantially radial axes and normal- 1y spring loaded into the closed position shown in dottedlines. "When the pulse jet is discarded, these vanes may be automatically moved by a suitablelinkage into the full-line position of Fig.

5 in which they olfer only-a small resistance to;

theuflowythrough the ram jet.

It is-t0,he,.understood that; the inventionis not limited to the specific embodir-r-rent;herein rounding a container, said ram jet having an inlet at one end and a thrust nozzle at the opposite A suitable ignitor 53 4 end, means for introducing fuel to said ram jet between the inlet and the nozzle, and igniter means aft of said fuel means, in combination with a pulse jet fitting in part within said thrust nozzle, said pulse jet having its open inlet end located within the ram jet and forward of said igniter means to receive the gas from said ram jet, said pulse jet including-a combustion chambar, and a-ithrust'nozzle communicatingwith and receiving the gas from the combustion chamber, said pulse jet having means externally thereof for guig-ling it within the first thrust nozzle, said pulse jet being substantially free to move rearwardly forremoval from the ram jet.

2. A missile including an annular ram jet surf rounding a container, said ram jet having an inlet at oneuend and a thrust nozzle at the opposite end, means for introducing fuel to said ram jet. between the inlet and the nozzle, and an igniter between said fuel means and the nozsubstantially free to move rearwardly for removal from the ram jet.

3. Amissile including an. annular ram jet surrounding a container, said ram jet having an inlet at one end and a thrust no-zzle at the op posite end, and means for introducing fuel to said" ram jet between the, inlet and the-nozzle, in combination with apulse jet fitting. in part within said thrust nozzle, said pulse jet. having its open inletend located within the ram jet to receive the'gastherefrom, a bank of valves adjacent the. inlet end of. the pulse jet for regulating the flow of gas thereto, said pulse jet including a combustion chamber, and a thrust nozzle communie.

eating with a-ndreceiving the gas from the combustion chamber, said pulse jet having means externally thereo-f for guiding it within the first thrust nozzle including anti-friction elements engaging the nozzlasaid pulse jet beingsubstantially free to moverearwardly for removal from the ram jet. 7

4.. A missile including-a substantially annular container, a duct surroundin and spacedfrom saldcontainer todefine an annular ram jet having an inlet at one end, the other end of theduct forming; acombustionqchamber and a thrust nozzle, said thrust nozzle. being. double walledwith; the. space. between said: walls receiving boundary-layer fromtheramjet forwardly of the combustion chamber-to provide for cooling the walls of the nozzle,

5. A'missile including a substantially annularcontainer,;a duct surrounding and spacfld from said container to define an annular ram jet having;aninlet atone end, the other end of. the duct forming a combustion chamber and a thrust. nozzle, said thrust nozzle being double, walled with the space between said walls receiving boundary layer from the ram jet forwardly of the combustion chamberto provide for cooling the. walls of the nozzle, in combination with a pulse jet fitting, at least in part, within said thrust nozzle, means on said pulse jet and engagillg with the inner wall of the nozzle for guiding the pulse jet for axial movement within the nozzle, cooperating means on the ram jet and pulse jet for limiting the forward movement of the pulse jet relative to the ram jet.

6. A ram jet including a duct having an inlet passage at one end and a thrust nozzle at the opposite end, means for introducing fuel to said ram jet between the inlet and the nozzle, and means for igniting said gases, in combination with a pulse jet partially positioned within said nozzle, said pulse jet having its open inlet end located within the ram jet to receive the gas therefrom, said pulse jet including a combustion chamber having the gases therein ignited by said ram jet igniting means, and a thrust nozzle communicating with and receiving gas from the combustion chamber.

7. A ram jet combination according to claim 6 wherein said pulse jet includes valve means positioned upstream of the pulse jet combustion chamber and said ram jet igniting means.

8. A ram jet including a duct having an inlet passage at one end and a thrust nozzle at the opposite end, and means for introducing fuel to said ram jet between the inlet and the nozzle in ram jet locating the combustion chamber for both said ram jet and said pulse jet.

9. A ram jet including a duct having an inlet passage, a combustion chamber, and a discharge passage in the form of a thrust nozzle, in combination with a pulse jet including a duct having an inlet located within the discharge passage and adjacent the combustion chamber of the ram jet, a bank of valves in said pulse jet inlet and a combustion chamber downstream thereof, said ram jet and pulse jet having cooperating means for limiting the forward movement of the pulse jet relative to the ram jet, and means for directing fuel from the ram jet to the pulse jet downcombination with a pulse jet partially positioned stream of said valves.

LOUIS S. BILLMAN.

References Cited in the'file of this patent UNITED STATES PATENTS Number Name Date 1,102,653 Goddard July 7, 1914 2,085,761 Lysholm July 6, 1937 2,246,429 Brandt June 17, 1941 2,419,866 Wilson Apr. 29, 1947 OTHER REFERENCES Article: The Launching of Guided Missiles, pp. 15-20, Coast Artillery Journal, March-April, 1947, pub. by U. S. Coast Artillery Assn., 631 Pa. Ave. NW., Washington 4, D. C.

Article: Jet Propulsion-Part I, pp. 10-17, Coast Artillery Journal, May-June 1947. 

